The present invention relates to improved confections which are intended to reside in the oral cavity for a period of time while being consumed. In particular, the present invention provides, among other things, medicinal tablets in which the medicinal off-taste commonly associated therewith is masked as the confection dissolves in the oral cavity.
Confections, and especially medicinal tablets which deliver active ingredients in the oral cavity, may be divided into various classes based upon their compositions or intended effect. Lozenges, compressed tablets and other medicinal tablets include breath fresheners, breath deodorants, cough suppressants, nasal decongestants and the like.
Over the years, considerable effort has been directed to improving sensory perception in the oral cavity of the volatile oils contained in confections. Often, such confections are perceived as having an unpleasant "medicinal" taste which tends to detract from the acceptance of such products. This unpleasant taste sensation is largely attributed to volatile oils included as part of the confection. Volatile oils or essential oils are derived from the leaves, stems or flowers of numerous plants and usually carry the savory or odorous principles of the plant obtained by distillation, expression or extraction. Volatile oils are known for their variable odors and distinctive tastes. Some are sweet, while others can be mild, pungent, hot, acrid, caustic or burning in taste. In addition, some volatile oils can be made synthetically. Masking the impression of volatile oil's medicinal off-taste in the oral cavity increases the benefit of the confection by ameliorating perceived bitterness, pungency, or other undesirable organoleptic sensations.
Menthol is isolated principally from the oil of Mentha arvensis. In its commercial form, menthol is present as 1-menthol crystals obtained from a process involving cooling of the oil. Fractional distillation of peppermint oil which usually contains from about 50% to about 65% menthol provides another important source of menthol. Synthetic sources of 1-menthol are also available.
The use of menthol for its medicinal effects is known in the art. Menthol's cooling effect to the mouth is useful to relieve local irritations in the throat and mouth.
Eucalyptus oil is another volatile oil thought to have therapeutic properties and is derived from the eucalyptus tree. Having a camphoraceous odor and cooling taste, this volatile oil is often combined with other essential oils such as those of menthol in confection formulations to impart medicinal effect. In particular, eucalyptus and its most active constituent, eucalyptol, are believed to be effective decongestants. Combinations of menthol and eucalyptus are widely used. When they are included in formulations capable of dissolving in the oral cavity, relief can be provided for coughs and minor mouth, throat, and upper respiratory irritations. Other uses of the methol/eucalyptus combination include mouthwashes, dentifrices and rubbing liniments.
Confections which include such medicinal formulations, e.g., cough drops, lozenges, etc., however, suffer from several shortcomings. For example, a bitter or "medicinal" taste and/or odor is often perceived due to the high potency of eucalyptus oil and eucalyptol. The strong taste and odor of the eucalyptus oil based confections released in the oral cavity, for example, provide an unpleasant organoleptic experience to many users, thus reducing the likelihood of continued treatment with the lozenge or tablet. In addition, prior art preparations containing eucalyptus suffer from erratic release of the eucalyptus vapors contained within the confection. Consequently, the cooling effect of eucalyptus has often been attenuated. These problems, therefore, tend to detract from the acceptance of eucalyptus-containing products as adjuncts in cough and cold therapy.
In addition to the above mentioned medicinal confections, oral hygiene products such as mouthwash may also contain menthol and/or eucalyptus as flavorants. While not ingested, these products also have been known to produce residual bitterness or medicinal off-taste in the oral cavity after expectoration of the oral hygiene product.
While not considered essential oils, borneol and fenchone are useful adjuvants in flavorings and, more importantly, in the fragrance industry. Borneol occurs in nature either as one of its enantiomers (levo or dextrorotatory) or as the racemic mixture. It can also be prepared synthetically. It has a camphor-like odor also described as a woody-peppery odor. In addition, borneol is characterized as having a burning taste. Borneol is most often found in incense-type of fragrances and room fresheners or pine odor products, however, to a lesser extent, borneol has been reported to be used in nut and spice flavors in trace amounts. Borneol is derived from natural sources such as trees found in Borneo. D-borneol occurs, for example, in camphor, rosemary, lavender and in olibanum oils, while 1-borneol occurs in oils or the pinaceae species. It, also, may be synthesized from camphor by hydrogen reduction or from alpha-pinene. The exo-isomer of borneol, iso-borneol, is not found in nature but is produce synthetically. This isomer has a similar organoleptic characteristic to borneol.
Fenchone is a ketone derived from oil of fennel and oil of thuja as well as from synthetic sources. Like borneol, fenchone has a camphoraceous odor and burning or bitter taste. Fenchone is most often used in industrial fragrances to mask odors. As a flavor chemical, fenchone is used in berry flavor and spice complexes or in certain type of liquor flavorings.
In the past, flavor and aroma enhancing or augmenting of volatile oil containing products has been undertaken. U.S. Pat. Nos. 4,269,862, 4,289,705, 4,303,725, and 4,320,771 all to Sprecker, et al. disclose enhancement of camphoraceous eucalyptus oil-like taste and/or fragrance in various products including foodstuffs with oxabicyclooctanes. This augmenting or enhancing, however, fails to solve the problem of medicinal off-tastes often associated with eucalyptus based products.
U.S. Pat. No. 4,252,828 to Mussinan, et al. discloses the use of synthetic bornyl ethyl ether to enhance or augment the flavor and/or aroma of various foodstuffs by imparting a camphoraceous, woody, eucalyptol-like aroma and taste to various flavoring adjuvants including essential oils.
U.S. Pat. No. 4,246,287 also to Mussinan, et al. discloses the use of fenchyl ethyl ether in a manner similar to that of bornyl ethyl ether to augment or enhance the flavor and/or aroma of various foodstuffs.
While the above mentioned patents to Mussinan, et al. disclose processes and compositions for augmenting or enhancing the flavor and/or aroma of foodstuffs with ethyl ethers of bornyl and fenchyl, there was no teaching or suggestion as to alcohol or ketone moieties such as d-borneol and fenchone having the ability to be combined with eucalyptus-containing confections to reduce or suppress the medicinal off-taste and commonly associated bitterness.
It is, therefore, an object of the present invention to provide an improved confection having the bitterness or medicinal off-taste of essential oils combined therein suppressed upon release of the essential oil into the oral cavity.
Another object of the present invention is to provide a natural food additive which masks the bitterness and unpleasant organoleptic sensations of essential oils as they are released in the oral cavity.